Well... thanks for responding anyway.  I'll keep researching and testing, but so far nothing I've tried will work.  I can't even export a template and import it (create a new portal) on the same DNN install (localhost). 

Ok, i had the same problem and i *think* it's a problem with the file manager in DNN 3.3.5. It needs to be perfectly synchronized, otherwise you will get the error when you try to create a site using a template WITH content.

If you can't synchronize your filemanager correctly, do this:

First, turn off caching (Host Settings / Advanced / others) and then manually clear the cache.

First, go in the HOST menu -> file manager and do a RECURSIVE synchronization.

Go in the ADMIN menu -> file manager and do a recursive synchronization. Make sure all the files in your Portal folder are the same as in the file manager menu. If the synchronization doesn't work (which is often the case of folders in the root portal folder), try adding a folder with the same name as the one that is not displaying. It will tell you the folder already exists and then it should show up in the file manager. Do this for all the folders that aren't displayed in the file manager.

Export the template from the site you a trying to export (ie: if you are trying to make a template off staging.com, then do it from staging.com). You can now using the .resources and .template file for creating new portals. If you still get the error, and you want to clear the half-created portal from your installation, do this:

Connect to SQL server
Go in the PORTALS table and find the ID of the portal to remove
Erase all rows from the MODULES table with the id of the portal as their Portal_id
Erase the portal entry from the Portals Table
Erase from the Users table the row which contains the administrator account created during the creation of the portal.
Go in aspnet_Users table and get the userid of the administrator
Erase from the aspnet_membership table the row which has the same user id as in aspnet_users
Erase the row from aspnet_user